The audio capabilities of personal computing systems are rapidly growing in sophistication. For example, computing systems are being equipped with CD and DVD players and digital multimedia software that make them attractive as personal multimedia systems, like personal stereos and video players. As such, the audio components and software of personal computing systems are adapting to satisfy the more demanding requirements of higher end audio systems. In addition, multimedia players are being equipped with audio components traditionally associated with personal computing systems, such as mixing features and title, artist, and lyric displays. As such, personal computing technology and digital audio technology are converging.
One relevant component in such audio systems is the interface between a digital audio source (e.g., DVD player or a sound card in a personal computer) and an audio receiver that drives the speakers. Traditionally, digital audio sources convert the digital audio into multiple analog signals before transmitting the audio signals to one or more speakers. In this configuration, multi-channel audio transmission is accomplished from the audio source over a set of analog connection wires to multiple speakers. One category of multi-channel audio is termed “6-channel audio”, which transmits audio signals over 6 analog connection wires between the source and the audio receiver. The 6 channels are devoted to two front speaker channels, two back speaker channels, one subwoofer channel, and one center channel. Another category of multi-channel audio, termed “8-channel audio” adds two side speaker channels.
Newer audio technologies, such as Dolby Digital and DTS, provide a compressed digital audio signal over a digital wired connection directly from the digital audio source to the audio receiver, thereby eliminating the need to provide 6/8 wire connections between the source and the audio receiver. The audio receiver then decodes the digital audio data and converts it to analog signals for the appropriate number of audio channels.
However, these technologies have been unable to fully exploit the advantages available in personal computing systems and newer digital audio equipment. For example, existing approaches do not adequately support adjustable compression levels, multiple sampling frequencies, or metadata.